#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
using namespace std;
class Sum {
public:
	Sum() {
		_ret += _i;
		++_i;
	}

	static int GetRet() {
		return _ret;
	}

private:
	static int _i;
	static int _ret;
};

int Sum::_i = 1;
int Sum::_ret = 0;

class Solution {
public:
	int Sum_Solution(int n) {
		Sum arr[n];

		return Sum::GetRet();
	}
};